This application claims priority of Taiwan Application No. 90214278, filed on Aug. 21, 2001.
1. Field of the Invention
The present invention relates to a wood-turning lathe, more particularly to a wood-turning lathe which is provided with an angular adjusting device for a driven shaft.
2. Description of the Related Art
Referring to FIG. 1, a conventional wood-turning lathe is shown to include a lathe bed 20, a headstock 21, a tail-stock (not shown), and a tool rest 24 between the headstock 21 and the tail-stock. The headstock 21, the tail-stock, and the tool rest 24 are mounted on the bed 20. The headstock 21 includes a headstock body 120 having a shaft 22 that is rotated by a motor (not shown), and that has a right clamping end 22xe2x80x2 extending outwardly from a right side of the headstock body 210 for holding one end of the woodpiece (not shown) to be turned. The tail-stock holds the other end of the woodpiece (not shown), allowing the latter to rotate freely. A chisel (not shown) is fixed on the tool rest 24 for shaping and cutting the woodpiece (not shown) during rotation of the latter. The headstock 21 further has a pulley unit (not visible) which is disposed inboard to a left side of the headstock body 210 and which is fixed on a left output end of the shaft 22. The pulley unit is formed with a plurality of circumferentially and angularly spaced retaining holes. The left side of the headstock body 210 is formed with a plurality of through holes 212 respectively registered with the retaining holes in the pulley unit in such a manner that after an angular adjustment of the shaft 22 relative to an index, a locking pin 23 can be inserted into a selected one of the retaining holes in the pulley unit and a corresponding one of the through holes 212 in the headstock body 210, thereby immobilizing the pulley unit relative to the headstock body 210. Under this condition, inscription or engraving can be done on an outer surface of the woodpiece using the chisel.
It is inconvenient for the user to insert the locking pin 23 into the headstock body 210 and the pulley unit. In addition, the locking pin 23 may be displaced since it is separately formed from the headstock body 210.
Therefore, the object of this invention is to provide a wood-turning lathe which includes an angular adjusting device for changing an angular position of a driven shaft with respect to a reference point and which is capable of immobilizing the driven shaft so as to avoid occurrence of the aforesaid disadvantages that result from the use of the conventional wood-turning lathe.
Accordingly, a wood-turning lathe of the present invention includes a lathe bed, a headstock, a tail-stock, and a tool rest between the headstock and the tail-stock. The headstock, the tail-stock and the tool rest are mounted on the lathe bed. The headstock includes a headstock body, a driven shaft, a drive shaft, first and second pulley units, a non-elastic belt, and an angular adjusting device for the driven shaft. The headstock body has a left side. The driven shaft is journalled to the headstock body, and has an output end extending outwardly from the left side of the headstock body. The drive shaft is journalled to the headstock body, and is vertically spaced apart from and extends parallel to the driven shaft. The drive shaft has a coupling end extending outwardly from the left side of the headstock body. The first and second pulley units are mounted respectively on the coupling end of the drive shaft and the output end of the driven shaft. One of the first and second pulley units has a side surface formed with a plurality of circumferentially and angularly spaced retaining holes. The non-elastic belt interconnects the first and second pulley units such that rotation of the drive shaft results in synchronous rotation of the first and second pulley units. The angular adjusting device includes a cam member and a cam follower. The cam member is mounted movably on the headstock body and defines a cam face. The cam member is movable between a locking position and an unlocking position. The cam follower is in the form of a spring-biased pin, and is disposed between the side surface of said one of the first and second pulley units and the cam member. The cam follower is urged to slidably contact the cam face such that when the cam member moves to the locking position, the pin is pushed by the cam face against biasing force thereof so as to engage the pin with a selected one of the retaining holes in said one of the first and second pulley units, thereby immobilizing the first and second pulley units. Under this condition, inscription or engraving can be done on an outer surface of a woodpiece which is held between the driven shaft and the tail stock. When the cam member moves to the unlocking position, the pin disengages from the selected one of the retaining holes in said one of the first and second pulley units, thereby permitting synchronous rotation of the first and second pulley units.
After angular adjustment of the driven shaft, a mere shifting of the cam member to the locking position results in immobilization of the driven shaft relative to the headstock body, thereby facilitating the user of the wood-turning lathe of the present invention. In addition, misplacement of components of the angular adjusting device, which occurs in the conventional wood-turning lathe, can be avoided.